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BMP-1
The BMP-1 is a Soviet amphibious tracked infantry fighting vehicle. BMP stands for Boyevaya Mashina Pekhoty (Russian: Боевая Машина Пехоты), meaning "fighting vehicle of infantry").[9] The BMP-1 was the world's first mass-produced infantry fighting vehicle (IFV).[6][10] It was called the M-1967, BMP and BMP-76PB by NATO before its correct designation was known.[11][12] It was a revolutionary design combining the properties of an armored personnel carrier (APC) and a light tank. The Soviet military leadership saw any future wars as being conducted with nuclear, chemical and biological weapons, where unprotected infantry would soon be either killed or incapacitated by radiation or chemical and biological agents. A vehicle like the BMP would allow infantry to operate from the relative safety of its armored, radiation shielded interior in contaminated areas and to fight alongside it in uncontaminated areas. It would increase infantry squad mobility, provide fire support to them, and also be able to fight alongside main battle tanks.[13] The BMP-1 was first tested in combat in the 1973 Yom Kippur War where it was used by Egyptian and Syrian forces. Based on lessons learned from this conflict and early experiences in the Soviet War in Afghanistan, a version with improved fighting qualities, the BMP-2 was developed. It was accepted into service in August 1980. In 1987, the BMP-3, a radically redesigned vehicle with a completely new weapon system, entered service in limited numbers with the Soviet Army. Development Mechanized infantry tactics during the 1950s were similar to World War II methods in which APCs were used as "battle taxis"; they brought their infantry up to the front line where they then dismounted and fought on foot while the APC provided suppressive fire from its on-board armament.[13] Existing APCs offered little or no protection from either nuclear or chemical weapons as they were either open-topped or could not be sealed sufficiently. Furthermore, the infantry had to disembark to be able to use their weapons.[13] The requirement for the BMP was first drawn up in the late 1950s. The requirement stressed speed, good armament, and the ability for all squad members to fire from within the vehicle. The armament had to provide direct support for dismounted infantry in the attack and defense and to be able to destroy comparable light armored vehicles.[14] The vehicle needed to protect the crew from .50 cal machinegun fire and 20–23 mm caliber autocannons across the frontal arc, as well as from light shell fragments at distances between 500 m and 800 m.[15] Firepower consisted of the innovative combination of the 73 mm 2A28 Grom gun and the newly developed 9S428 anti tank wire guided missile (ATGM) launcher for the 9M14 Malyutka (AT-3A Sagger A) ATGMs. The gun was intended to engage enemy armored vehicles and firing points at a range of up to 700 metres (770 yd), while the missile launcher was intended to be used against targets that were 500 metres (550 yd) to 3,000 metres (3,300 yd) away.[15] Requirements were issued to the various design bureaus between 1959 and 1960. There was a question as to whether the BMP should be tracked or wheeled, so a number of experimental configurations were explored including hybrid wheeled/tracked designs.[1] The tracked Ob'yekt 764 was chosen because its front engine design provided a convenient and fast way of mounting and dismounting through two rear doors. The original production prototype, which was built in 1965, was designated BMP.[16] Small scale production began in 1966.[1] Models A large number of variants of the BMP-1 were produced. The most notable IFV variants based on the BMP-1 were: BMP-2, MLI-84 and Boragh. Table of models Characteristics of the main models of the BMP series Production history The BMP went into production with the Soviet Army in 1966. The first series (the Ob'yekt 765Sp1), was produced until 1969 but was replaced by the improved production model, the BMP-1 (the Ob'yekt 765Sp2), it was produced from 1969 until 1973. It was replaced by the Ob'yekt 765Sp3 which was a modernized, 200 kg heavier version. This model was produced from 1973 to 1979. A number of improvements were made to the reliability of the chassis, the engine and transmission during mass production. The last version of the BMP-1 IFV (BMP-1P, Ob'yekt 765Sp4), was armed with a more powerful ATGM launcher 9P135M-1 for the ATGM "Konkurs"/"Fagot" It was produced from 1979 to 1983. The main manufacturer of the BMP-1 and its different variants was the Kurgan Machine Building Works (Kurganskiy Mashinostroitelyniy Zavod) but PRP-3 artillery reconnaissance vehicles were produced by the Chelyabinsk Tractor Works (ChTZ) and PRP-4/PRP-4M artillery reconnaissance vehicles were produced by the Rubtsovsk Engineering Works (RMZ). Upgrades of the BMP-1 were performed by KMZ as well as by tank repair workshops of the Ministry of Defence during scheduled and major overhauls. More than 20,000 BMP-1''s'' and vehicles based on it were built in the USSR. BMP-1''s'' were produced under license by Czechoslovakia, Poland,[16] Romania (MLI-84) and India.[16] Since 1986 the People's Republic of China has produced its own unlicensed copy called the Type 86 (WZ 501). The number of Type 86 IFVs and vehicles based on it is around 3,000[3] It is still in service with the People's Liberation Army. From 1997, Iran produced its own modification of the BMP-1, the Boragh, it resembles the Chinese WZ 503. Czechoslovak BVP-1''s'' were produced by ZTS Dubnica nad Váhom. 274 Polish BWP-1''s'' were built by the Wojskowe Zakłady Motoryzacyjne Nr. 5 (WZM Nr. 5) (Military Motorization Plant No. 5) in Poznań until 1988 (1406 were bought from the Soviet Union).[18][19] It still produces spare parts for the BWP-1 and UTD-20 diesel engines. Its design bureau has developed a modernization package for the BWP-1. It built several prototypes of different turrets including unmanned ones. There was also one prototype with the original turret.[20] Modernization In the mid 1970s, after analysis of the use of light AFVs during the Yom Kippur, Angolan and Vietnam wars, a modernization program was begun that resulted in the BMP-1P (Ob'yekt 765Sp4). The main changes were the replacement of the largely ineffective 9S428 ATGM launcher and the 9M14M Malyutka ATGM with the more reliable, longer range and more powerful 9P135M or 9P135M-1 ATGM launcher.[21] It was located on a special pintle mount on top of the roof of the turret, that could fire the SACLOS guided 9M113 and 9M113M Konkurs-M ATGMs,[21] which increased armor penetration to 670 mm (26 in) and had an extended range of 4,000 m (4,400 yd). The 9P135M-1 launcher was also capable of firing 9M111 and 9M111-2 Fagot ATGMs. The Malyutka loading hatch was usually welded shut and the mounting bracket was removed. The new missiles were somewhat difficult to use since the gunner had to stand in his open hatch to use the weapon, exposing himself to hostile fire.[21] It is possible to detach the 9P135M(1) ATGM launcher from the turret and use it from the ground. The BMP-1P was equipped with neutron weapon protection covering and a new fire-extinguishing system for protection against napalm. Later BMP-1Ps were fitted with an array of six 902V "Tucha" 81 millimetres (3.2 in) calibre smoke grenade launchers at the rear of the turret.[21] Some were also equipped with the track-width KMT-10 mine plow. The BMP-1P replaced the BMP-1 in production in 1979 and many BMP-1s were upgraded to the new standard during the 1980s.[21] The BMP-1PG model added the 30 mm (1.2 in) AGS-17 "Plamya" automatic grenade launcher on the left hand side of the top of the turret, for which it carries 290 grenades. Some BMP-1s had the AGS-17 added during major repairs (Ob'yekt 765Sp8). A non-amphibious BMP-1D (the so-called 'Afghan' variant), was built in 1982 for assault units in Afghanistan. It had 5 mm thick appliqué steel armor plates on the hull sides with holes for side firing ports as well as armor plate under the commander's and driver's seats for added protection against mines. It also had large steel armored skirts fitted to the sides of the hull covering the suspension. Firing ports were added into the top hatches of the troop compartment and a stowage box was placed on the roof at the rear of the hull on some vehicles. The 9S428 ATGM launcher was often removed and replaced by an AGS-17 automatic grenade launcher. Due to experience in Afghanistan, a new version with enhanced fighting capabilities, the BMP-2, was introduced in 1980. It had a new two-man turret armed with a 30 mm 2A42 multi-purpose autocannon and a 9P135M-1 ATGM launcher capable of firing SACLOS guided [http://en.wikipedia.org/wiki/9M113_Konkurs 9M113 Konkurs] and 9M113M Konkurs-M as well as 9M111 and 9M111-2 Fagot ATGMs. Later modernization plans included mounting the turret of the BMD-2 IFV on BMP-1s but the vehicle never left the design phase. Recent proposals for the modernization of BMP-1s include mounting new turrets armed with a 25 to 30 mm (0.98 to 1.2 in) autocannon, or a TKB-799 Kliver one-man weapons station with a computerized fire control system, armed with a missile pod (which can be armed with either four [http://en.wikipedia.org/wiki/9M133_Kornet 9M133 Kornet] (AT-14 Spriggan) or 9M133F Kornet ATGMs or [http://en.wikipedia.org/wiki/9K38_Igla 9K38 Igla] (SA-18 Grouse) SAMs), a 30 mm 2A72 dual-purpose autocannon and a 7.62 mm (0.300 in) PKTM coaxial machine gun (BMP-1M).[5][22] See BMP-1 variants article for complete list of BMP-1 modifications and variants based on it. Description The BMP-1 is a fully amphibious tracked vehicle, with a front-engined chassis developed especially for it, a welded steel hull with a sharp, sloping front with a conspicuously ridged surface, a centrally located, flat, truncated cone turret and a troop compartment at the rear.[23] Driver's station The driver sits in the front on the left side of the hull. He has three TNPO-170 periscope vision-blocks to provide vision when his hatch is closed.[24] The driver's center vision block can be replaced with a TVNO-2 active night binocular vision device for use in night and poor visibility conditions or with a TNPO-350B extended periscope when swimming with the trim vane erected.[7][24] The BMP was the first Soviet armored vehicle to use a simple yoke steering system.[25] Commander's station The commander's station is located behind the driver's station and is provided with a removable OU-3GA2 or OU-3GK infrared searchlight with an effective range of about 400 metres (440 yd).[26] A dual mode (day/night) TKN-3B 5x/4.2x magnification binocular vision device is coupled to the infrared searchlight. Two periscope vision blocks are also fitted with a heating and cleaning system.[27][28] The commander's station is equipped with a R-123M radio set. Turret The BMP-1 has a conical turret equipped with a fume extraction system and an electric traverse drive with a manual backup system.[12] The main gun has a dead-zone over the commander's hatch (between the 10:00 and 11:00 o'clock positions), where the gun must be elevated over the infra-red searchlight to avoid crushing it. When the gun is facing backwards it prevents hatches on top of the troop compartment from opening. The low profile of the turret means that the barrel of the gun is less than six feet off the ground, so it cannot be fired over the heads of advancing infantry.[11][29] On the other hand, the low profile of the turret makes it a difficult target. The same turret is used in the BMD-1. Gunner's station The gunner's station is located to the left of the main gun. The gunner has a dual mode (day/night) 1PN22M1 6x/6.7x magnification image intensifying monocular periscope sight, four day-use periscope vision blocks, an optical rangefinder and a OU-3GK removable infrared or white-light searchlight.[28] The 1PN22M1 sight has a maximum range of 400 metres (440 yd) at night, 900 metres (980 yd) with the use of the infra-red searchlight.[6][23][28] The sight is marked stadiametricly with the apparent size of a 2.7 metres (8.9 ft) tall tank at various ranges. The original sight was replaced with the 1PN22M2, which has an additional scale for the OG-15V HE-Frag rounds used by the Ob'yekt 765Sp3, produced from July 1974. The new sight has two day scales for the two projectiles - one from 200 to 1,600 metres (220 to 1,700 yd) and the other from 400 to 1,300 metres (440 to 1,400 yd).[28] Armament Gun Main armament is the 73 mm 2A28 "Grom" low pressure smoothbore semi-automatic gun. It is fed from a forty round magazine located around the turret ring.[30] Cyclic rate of fire is 8 to 10 rounds per minute, with the gun returning to an elevation of +3° 30' to reload after each shot if the autoloader is used. The gun can be reloaded by hand if necessary. The autoloader is unreliable and can be dangerous to the crew.[8][30] Some units removed the autoloader altogether when new vehicles were delivered, but the mechanized ammunition conveyor magazine was kept. The 2A28 'Grom' smoothbore gun fires the same PG-15V projectiles as the SPG-9 infantry light recoilless gun but with a smaller propellant charge. The PG15V HEAT warhead can penetrate 280 to 350 mm (11 to 14 in) of steel armor - more than enough to penetrate the frontal armor of NATO MBTs of the 1970s, such as the US M60A1, the British Chieftain or the German Leopard 1.[30] The modernized PG-9 shell is able to penetrate up to 400 mm (16 in) of steel armor. This gun is unable to penetrate the front armor of modern NATO MBTs such as the US M1A1 Abrams, the British Challenger 2, or the German Leopard 2, but it has been claimed that it can penetrate the side armor of these tanks in some areas.[31] Under battlefield conditions it has a maximum effective range of 500 m (550 yd).[32] OG-15V high explosive ammunition was made available in the 1970s. The warhead has twice the weight of explosives as the anti-armor PG-15V; it is intended for use against troops or soft targets.[30] A coaxial 7.62 mm PKT machine gun is mounted to the right of the main armament[30] for which the BMP-1 carries 2,000 rounds.[33] The 2A28 'Grom' gun and PKT coaxial machine gun cannot be accurately fired while the vehicle is on the move over rough ground as the turret is unstabilised.[30] ;Missile Mounted on the gun mantlet, the 9S428 ATGM launcher is capable of firing the [http://en.wikipedia.org/wiki/9M14_Malyutka 9M14 Malyutka], (NATO: AT-3A Sagger A); the 9M14M Malyutka-M (NATO: AT-3B Sagger B) and the 9M14P Malyutka-P (NATO: AT-3C Sagger C), all of which are intended to be used against enemy MBTs and other AFVs at distances from 500 to 3,000 m (550 to 3,300 yd). These ATGMs can penetrate up to 560 mm (22 in) of steel armor (NATO standard at the time).[6] The BMP-1 carries 5 ATGMs (one on the launching rail, two inside the turret and two inside the hull). Each 9M14M weighs 10.9 kg (24 lb), a 9M14P with semi-automatic control is 11.4 kg (25 lb). These missiles can only be fired in daylight because it lacks a night sight. Besides such advantages as interference immunity and simple control equipment, wire-guided ATGMs are hampered by significant disadvantages such as: a relatively low flight speed, response delay, the inability to load a new missile until the previous one has reached its target and a very long minimum range (500 m (550 yd)).[12] Successful operation of the ATGM while the vehicle is on the move requires a very skilled gunner. BMP-1s that were not modernized to BMP-1P standard now in Russian service can use 9M14-2 Malyutka-2 (NATO: AT-3D Sagger D) ATGMs (developed in 1995), which have either a tandem shaped-charge or high-explosive thermobaric warhead.[11][34] The BMP-1 was a threat to NATO APCs, light AFVs, and even MBTs of its time, by use of its main gun or ATGM. Nevertheless, the strong anti-tank focus of its armament didn't provide sufficient firepower against enemy unarmored vehicles, infantry and light fortified positions, especially during mountain battles, (mostly due to the low elevation angle of the main gun). The appearance of the more successful BMP-2 armed with the 30 mm 2A42 dual-purpose autocannon solved this serious problem.[citation needed] Troop compartment The troop compartment located at the rear of the vehicle can carry up to eight soldiers. There are four firing ports on each side of the vehicle and a single firing port in the left rear door; a combination fume extractor hose and cartridge deflector is provided to clip on to weapons at each station.[35] Soldiers sit on two padded benches along the center line of the vehicle and face the sides. Vehicle batteries, electric equipment and the main 330 l (73 imp gal; 87 US gal) fuel tank are located between the benches, with tool stowage beneath.[35] There are four large D-shaped hatches in the roof of the hull which can be opened from the troop compartment. The airtight rear doors of the troop compartment also contain fuel tanks.[35] Space inside the troop compartment is limited. There is little room for personal equipment, which leads to it being stowed outside while on operation, sometimes limiting rearward traverse of the turret. The seating is also cramped, especially for troops in full battle dress, leading to some armies reducing troop capacity to seven.[35] Maneuverability The 300 horsepower (224 kW) UTD-20 six cylinder four stroke diesel engine is located in the centre of the front hull, behind the transmission, with the cooling system to the right and radiator above.[36] The engine drives a manual gearbox with five forward and one reverse gear.[7] The fuel tanks have a maximum capacity of 462 liters. The diesel engine is of a multifuel design and can use DL (summer) or DZ (winter). It can also use TS-1 kerosene.[37] The BMP-1 has a maximum road speed of 65 kilometres per hour (40 mph), which is reduced to around 45 kilometres per hour (28 mph) off-road.[6][11] The BMP-1 can climb 0.7 metres (2.3 ft) high vertical obstacles, and cross 2.5 metres (2.7 yd) wide trenches. It can be driven on 25° side slopes and can climb 35° gradients.[6][16][38] Drive sprockets are at the front with six road wheels, using torsion bar suspension.[23] The BMP-1 has a ground pressure of (0.6 kg/cm²) and is able to cross snow-covered and boggy terrain. It has the range, off-road speed and cross-country ability necessary to keep up with fast-moving MBTs. Amphibious capability The BMP-1 is amphibious, propelling itself in the water using its tracks, assisted by hydrodynamic fairings on the track upper side covers. Top swimming speed is 8 kilometres per hour (5.0 mph). The shape of the hull and some features (hollow road wheels and road wheel arms with air chambers) aid flotation. The BMP-1 can overcome water barriers with a current speed up to 1.2 metres (1.3 yd) per second and waves up to 0.25 metres (0.82 ft) high. More challenging conditions require engineer support.[6] Before entering the water the trim vane at the front of the hull should be erected to prevent water from flooding over the bow. While in its traveling position it serves as additional frontal armor. The rear doors of the troop compartment must be closed tightly before entering the water. The BMP-1 can cross water obstacles such as rivers and lakes but it is not intended for sea landing operations. Armor protection The vehicle's armor is welded rolled steel varying in thickness between 6 millimetres (0.24 in) thick on the top of the hull and 33 millimetres (1.3 in) on the mantlet of the main gun.[7] The original requirements called for protection against 23 millimeter armor-piercing rounds across the frontal arc fired from 500 metres (550 yd) and for protection against 7.62 millimeter armor-piercing rounds across the side and rear arcs from 75 metres (82 yd). The BMP-1's steeply sloped frontal armor can withstand artillery shell fragments, small arms fire and existing .50 caliber (12.7 mm) heavy machine gun AP and API rounds over 60° of the frontal arc from all distances.[12] The very high angle of the hull frontal armor increases the probability of ricochets, and the trim vane in the traveling position adds little additional protection. On most examples the front armor is immune to 20 millimeter Oerlikon KAD or HS820 auto-cannon fire from ranges greater than 100 meters, but armor quality varies quite significantly with the nationality of a factory. The side, rear and top armor protect the BMP-1 from 7.62 mm small arms fire from most distances as well as smaller artillery shell fragments but do not protect the vehicle against 12.7 mm heavy machine gun fire from close distances or larger artillery shell fragments. Nevertheless, ground tests demonstrated that rear doors with fuel tanks filled with sand withstood hits from standard 12.7 mm rounds.[6] In Afghanistan and Chechnya armor-piercing 7.62 mm rounds fired from general purpose machine guns at ranges of around 30 – 50 m sometimes penetrated the rear doors and hatches.[39] During the First Persian Gulf War the armor protection of the BMP-1 proved vulnerable to the armor-piercing rounds of the US M2/M3 Bradley's 25 millimetres (0.98 in) M242 Bushmaster autocannon.[40] During the intense fighting in Chechnya, no penetration of the BMP-1/BMD-1 turret front armor were noticed because the turret made for a small target and had relatively thick frontal armor compared to other parts of the vehicle.[41] Armor[7] Protection issues The BMP-1 had significant shortcomings in its protection scheme, which only became obvious during the Soviet War in Afghanistan. It seats its driver and commander in a tandem layout, on the left hand side of the front of the hull alongside the diesel engine. When an antitank mine hits the BMP-1's left track, the explosion usually destroyed one to three left hand side roadwheels, penetrated the bottom and killed or seriously wounded the driver and the commander which caused painful losses of specialist personnel in the Soviet Army. Drivers laid sandbags on the bottom of their compartment in an effort to protect themselves against possible mine attack. The same kind of explosion under the right track were much less dramatic for the driver and the commander who remained relatively safe.[39] If the vehicle hit a tilt-rod antitank mine, its steeply sloped lower front glacis plate allowed the mine's arming rod to tilt with little resistance until the mine was well under the chassis. When it eventually detonated, the blast was usually sufficient to kill or badly wound the driver and the commander. The Soviet 40th Army in Afghanistan began to receive improved BMP-1Ds (the so-called "Afghan" variant) from 1982 onward which, among other improvements, included an additional armored plate under the driver's and commander's stations. This situation was addressed in the later BMP-2 design, where the commander shares the two-man turret with the gunner. The driver's and engine compartments could be equipped with additional bottom armor for improved protection against landmines filled with up to 2.5 kilograms (5.5 lb) of explosives.There is also a protection issue concerning the reloading of the 9M14 "Malyutka" and 9M14M "Malyutka-M" ATGMs in NBC conditions because doing it through the small hatch from inside the vehicle would destroy whatever protection the fighting compartment's NBC protection suite gave. The compactness and low silhouette of the vehicle are generally advantages on a battlefield. Critical areas such as the engine compartment and ammunition storage area, fuel cells and the troop compartment are located in such a manner that became the standard for many IFVs and APCs. Penetration anywhere in these areas will often result in mobility and/or firepower damage and/or disabling of the personnel.[11] BMP-1 and BMP-2 series vehicles share a major drawback with many Soviet tanks. Ammunition is stored near or even inside the fighting compartment which makes them more vulnerable to a hit from an anti-tank round or a missile across the side arc. If that happens, the ammunition often explodes, killing everyone and completely destroying the vehicle.[40] During the fighting in Afghanistan and Chechnya, hits by rocket-propelled grenades (RPGs) penetrated the BMP-1's armor in 95% of cases. This often resulted in the vehicle burning until the ammunition exploded.[39] Due to these limitations, Soviet/Russian soldiers customarily rode on the outside of the BMP-1, sitting on top of the hull while in combat zones. This tactic had also been adopted by their American counterparts during the Vietnam war, when they found their own M113 APCs were vulnerable to RPG attack. It has an obvious downside on the likelihood of passenger survivability in a war-zone. The armor of BMP-1 IFVs is also insufficient to deal with AP cannon rounds - sufficiently thick armor would increase the weight of the BMP-1 considerably and jeopardize its amphibious ability. Some military analysts support the idea of returning to the concept of open-topped APCs as the armor of light AFVs cannot protect the crew from anti-tank weapons. Modern APCs are mostly used in local conflicts instead of hypothetical large-scale wars with NBC weapons. The problem most often cited by western analysts is the design of the main fuel tank. Due to the low profile of the vehicle the designers have had to place the fuel tank between the two rows of outward-facing seats, meaning that the infantrymen sit very close to the bulk of the vehicle's fuel storage, extra fuel is carried in the hollow armored rear doors. Therefore a hit by an armor-piercing incendiary round would set the fuel contained there (especially, if kerosene is used instead of diesel), on fire. The burning fuel would move into the crew compartment, resulting in the death or injury to the infantrymen (if they are unable to leave the vehicle via the roof hatches), and a possible explosion. However, the rear door tanks are almost always empty when the BMP goes into combat as they are only meant to increase the road travel range of the vehicle. In intense war areas where the BMP sees action often and it is relatively near to its base of operations, instructions highly recommend detaching the rear door tanks from the fuel system, filling them with sand as additional protection of the troop compartment and adding fuel to the internal main fuel tank from other sources when the need arises. This was not practiced by some crews of BMP-1s during a number of local conflicts, e.g., in Chechnya, which resulted in frequent attempts by the enemy to hit the rear doors of the BMP-1s. The inner fuel tank is more vulnerable than that of many modern IFVs - the thin side armor means that penetration is likely to occur to the inner fuel tank as well. Another potential flaw in the BMP-1 is its troop seating layout. In order to allow the infantrymen to use their assault rifles and machine guns while on the move, firing ports were installed in the sides of the hull and in the left rear door. Soldiers are seated on two back-to-back benches, mounted along the center line of the troop compartment. If hit by a more advanced type of magnetic anti-tank mine, the resulting explosion could kill the entire complement of infantrymen. In many other troop carriers, soldiers are seated on separate benches against the hull sides. This layout might prohibit the use of infantry weapons from inside the troop compartment, but in most cases the loss of life from a mine would be significantly less, although the loss of lower limbs would still be frequent. It should also be noted that most conscript soldiers do not receive much training in firing from inside the vehicle while it's moving. Even for professional soldiers, the unstabilized firing port periscopes makes it very difficult to conduct aimed fire while on the move. Nevertheless, the ability of soldiers to use their weapons from inside the vehicle is of extreme importance during urban warfare, especially, when repulsing enemy ambushes. The BMP-1 has no air conditioning or air cooling system, its crew members and passengers suffer heavily in hot climates as its air filtration system and exhaust-ventilation fans cannot provide any comfort at high temperatures.[39] During the Yom Kippur War crews kept some of the roof hatches open. This meant that they were vulnerable to machine gun fire from higher ground. Only a few examples of the BMP-1 were intended for export - mainly to countries with a hot climate (for example, the Slovak-Belorussian "Cobra-S"), they are equipped with an air conditioning system. The cooling system for the engine is improved, as is the additional forced air cooling system of the engine compartment and radiator. The exhaust system helps to eject gases together with hot air from the engine compartment through the grille located on the right-hand side of the hull roof in front of the turret. Equipment The BMP-1 can make its own smoke screen by injecting vaporized diesel fuel into the exhaust manifold using the TDA engine thermal smoke generating system.[42] Later models also have an array of 902V Tucha smoke grenade launchers which can form a screen 80 m (87 yd) wide, 200 to 300 m (220 to 330 yd) in front of the vehicle.[42] A number of BMP-1s were fitted with mountings for the KMT-10 plow-type of mine-clearing system in the early 1980s. It is installed on the front of the hull in line with the tracks. The plow weighs 450 kg (990 lb) and can be attached in 30 minutes, emergency detaching takes around 10 minutes. The KMT-10 is intended for clearing anti-tank mines under different ground conditions. It is pneumatically-driven and takes 4 seconds to switch from the traveling position to the digging position. The mine-clearing plows are very narrow, with just two digging tines, each 300 mm (12 in) wide, (the same as each track), which limits them to clearing surface-laid mines, in particular scatterable anti-tank mines. A chain mounted between the plows can detonate tilt-rod mines. Maximum mine-clearing speed is 15 km/h (9.3 mph).[12][43][44] When the NBC protection system is configured and operating, the crew and passengers are protected from chemical weapons, biological agents and nuclear fallout by an air filtration and overpressure system which consists of the NBC filter element and the blower/dust separator.[12] BMP-1s were equipped with one RPG-7/RPG-7V [5] shoulder-launched anti-tank rocket-propelled grenade (RPG) and five PG-7 rounds or one 9K32 Strela-2/9K38 Igla man-portable anti-aircraft missile launcher and two replacement missiles.[23] It carries 1600 rounds for two PK general-purpose machine guns. Service history Soviet Union and Russia The BMP-1 entered service with the Soviet Army in 1966. The BMP-1 was first seen by westerners during the 7 November 1967 military parade in Moscow. Its appearance created a stir in the West where lightly-armed APCs were still the norm for transportation and infantry support on the battlefield. In the Soviet Army, BMP-1s were typically issued to motorized rifle divisions and the motorized rifle regiments of tank divisions, where they replaced the BTR-152, BTR-50P and some BTR-60P APCs. Currently, BMP-1s and vehicles based on it are used by the Russian Army and internal security troops of the Russian Ministry of Internal Affairs (MVD). Afghanistan BMP-1s were widely used in Afghanistan by motorized rifle and tank units. They were also operated by some special forces. Due to its lackluster performance, a new up-armored variant, designated the BMP-1D (the so-called 'Afghan' variant), was rushed into service in 1982. Many field modifications were made to their BMP-1s by various units. Others Other BMP operators have included Poland, Egypt, Syria, the People's Republic of China, Afghanistan, India, Iraq, Germany, Greece, and Sweden.